Multiple projector systems have been proposed and used for many years. In the 1950s, the “CINERAMA” system was developed for the film industry. The CINERAMA system used three films to project three images using three separate projectors, which were then combined to form a single panoramic image.
A difficulty with multiple projector display systems is that the multiple images often do not appear as one single continuous image on the display screen. When two images are projected side by-side on a single screen, there is normally a seam between the images. The final display image will either appear as two images placed side-by-side with a gap there-between or, if the images are made to overlap on a single screen, with a bright line there-between. Because of the inconsistencies in conventional cameras, video processing and delivery channels, displays and specifically projectors, it is exceedingly difficult to perfectly match the resultant video images so that no tiling artifact appears among the images. If the images are brought very close together on the same screen, there are typically overlaps at each seam regions.
Therefore, systems and methods for providing generally seamless images in multiple projector display systems are needed. Furthermore, projector lens inherently distort images to some extent especially at the edges of the lenses. It is desirable that distortion in the displayed images be minimized, especially at the edges of the lenses, since this area of the lens is more likely to project images displayed closest to seams.
Conventional electronic distortion correction involves capturing, with a video image capture device, an image as it is displayed and generating feedback signals representative of the displayed distortion. Feedback signals are used to cancel out the distortion. Such a solution provides some improvement to the problem of lens distortion. However, among other drawbacks, this type of electronic distortion correction itself can add distortion, often adds to system complexity and cost, and complicates calibration and user interfaces.
Therefore, systems and methods are needed for tiled display systems which do not include visually disturbing seams between the tiles. Further, there is a need for a tiled display system which merges together projected images from multiple tiles to form a tiled image, but which does not require high-quality (and expensive) optics. Therefore, a system that can electronically compensate for lens distortion is needed. Further systems that can adjust for lens distortion without relying solely on external capture of the displayed image are desirable. Further systems and methods are needed that, provide a broader viewing angle than existing systems, while, at the sametime, more effectively concealing seams in tiled images.